1. Field of the Invention
The present invention relates to a substrate processing apparatus for subjecting substrates to processing.
2. Description of the Background Art
Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, and photomasks, and other substrates to various types of processing.
Such a substrate processing apparatus generally subjects a single substrate to a plurality of different types of processing successively. The substrate processing apparatus as described in JP 2003-324139 A comprises an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-mentioned substrate processing apparatus, a substrate carried out of the indexer block is transported to the exposure device through the interface block after being subjected to anti-reflection film formation and resist film coating processing in the anti-reflection film processing block and the resist film processing block. After the resist film on the substrate is subjected to exposure processing in the exposure device, the substrate is transported to the development processing block through the interface block. After the resist film on the substrate is subjected to development processing to form a resist pattern thereon in the development processing block, the substrate is transported to the indexer block.
With recent increases in density and integration of devices, making finer resist patterns has become an important problem. Conventional exposure devices have generally performed exposure processing by reduction-projecting a reticle pattern on a substrate through a projection lens. With such conventional exposure devices, however, the line width of an exposure pattern is determined by the wavelength of a light source of the exposure device. Therefore, making finer resist patterns has had a limitation.
Therefore, a liquid immersion method is suggested as a projection exposure method allowing for finer exposure patterns (see, e.g., WO99/49504 pamphlet). In the projection exposure device according to the WO99/49504 pamphlet, an area between a projection optical system and a substrate is filled with a liquid, resulting in a shorter wavelength of exposure light on a main surface of the substrate. This allows for finer exposure patterns.
However, in the projection exposure device according to the above-mentioned WO99/49504 pamphlet, exposure processing is performed with the substrate and the liquid being in contact with each other. Accordingly, the substrate to which the liquid adheres is carried out of the exposure device. When the exposure device using the liquid immersion method as described in the above-mentioned WO99/49504 pamphlet is provided as an external device in the substrate processing apparatus according to the above-mentioned JP 2003-324139 A, therefore, the liquid adhering to the substrate that has been carried out of the exposure device may drop in the substrate processing apparatus, causing operational troubles such as abnormalities in an electric system of the substrate processing apparatus.
When the liquid adheres to the substrate that has been subjected to the exposure processing, particles and the like may adhere to the substrate. When the particles and the like adhere to the substrate, processing defects may occur in the substrate.